The primary objective of our program is to find conditions under which preformed polynucleotide chains direct the non-enzymatic synthesis of their complements according to the Watson-Crick pairing rules. The incorporation of adenosine-5'-phosphate and guanosine-5'-phosphate into oligomers on poly (U) and poly (C) templates, respectively, is readily achieved, but the corresponding reactions of pyrimidine nucleotides do not occur. We plan to extend our work on the incorporation of pyrimidine-containing dinucleotides such as pUpG and pCpA into oligomers. Prelminary studies show that incorporation takes place efficiently, on appropriate templates. We also hope to synthesize the 2'-amino-2'-deoxynucleotides and to carry out template-directed condensations using these analogues and their oligomers. Our preliminary experiments show that these amino-nucleotides condense about 100 times more efficiently than the corresponding nucleotides under a variety of conditions. We expect that it will prove relatively straightforward to achieve template-directed synthesis of long oligomers in this way. While this work is not directly related to the origins of life on earth, we expect it to throw much new light on the evolution of self-replicating polymers.